A variety of regulatory molecules, known as cytokines, have been identified including interleukin-11 (IL-11). The various protein forms of IL-11 and DNA encoding various forms of IL-11 activity are described in Bennett, et al., U.S. Pat. No. 5,215,895 (Jun. 1, 1993); McCoy, et al., U.S. Pat. No. 5,270,181 (Dec. 14, 1993); and McCoy, et al., U.S. Pat. No. 5,292,646 (Mar. 8, 1994), all incorporated herein by reference. Thus, the term "IL-11" includes proteins having the biological activity described in these patents, whether produced by recombinant genetic engineering techniques; purified from cell sources producing the factor naturally or upon induction with other factors; or synthesized by chemical techniques; or a combination of the foregoing.
IL-11 is a pleiotropic cytokine that has been implicated in production of several biological activities including: induction of multipotential hematopoietic progenitor cell proliferation (Musashi et al. (1991) Blood, 78, 1448-1451); enhancement of megakaryocyte and platelet formation (Burstein et al. (1992) J. Cell. Physiol., 153, 305-312); stimulation of acute phase protein synthesis (Baumann et al. (1991) J. Biol. Chem., 266, 20424-20427); inhibition of adipocyte lipoprotein lipase activity (Kawashima et al. (1991) FEBS Lett., 283, 199-202); and effects on neurotransmitter phenotype (Fann et al. (1994) Proc. Natl. Acad. Sci. USA, 91, 43-47).
IL-11 may be used in a pharmaceutical preparation or formulation to treat immune deficiencies, specifically deficiencies in hematopoietic progenitor cells, or disorders relating thereto. Treatment of the other disorders or stimulation of the immune systems of cells thereof may also employ IL-11. IL-11 may also be employed in methods for treating cancer and other disease. Such pathological states may result from disease, exposure to radiation or drugs, and include, for example, leukopenia, bacterial and viral infections, anemia, B cell or T cell deficiencies such as immune cell or hematopoietic cell deficiency following a bone marrow transplantation. IL-11 may also be used to potentiate the immune response to a variety of vaccines creating longer lasting and more effective immunity. Therapeutic treatment of cancer and other diseases with IL-11 may avoid undesirable side effects caused by treatment with presently available drugs.
Like most cytokines, IL-11 exhibits certain biological activities by interacting with an IL-11 receptor (IL-11R) on the surface of target cells. It would be desirable to identify and clone the sequence for the human receptor so that IL-11R proteins can be produced for various reasons, including production of therapeutics and screening for inhibitors of IL-11 binding to the receptor and receptor signalling.